What equivalent attribute in Xilinx IDE

[fl]

Hi,

I see an example on Xilinx FPGA with tool Synplify-Pro:

attribute syn_multstyle : string;
attribute syn_multstyle of MULT : signal is "logic";


I only have Xilinx IDE. How can I get the above constraint in IDE?
I am working on Xilinx Spartan-6.

Thanks,